Large object (LOB) is a data type, including the following three types: the binary large object (BLOB) data type, which is used to store binary data such as an image; the character large object (CLOB) data type, which is used to store character data, such as a text file; and the double byte character large object (DBCLOB) data type, which is used to store double-byte character data. A stored object corresponding to the LOB data type may be a very large image or file, and therefore, compared with other data types, the LOB data type has special storage requirements.
Because the size of a LOB is usually very large, larger even than the maximum database row size, a group of LOBs cannot be stored together using basic row based database storage schemes. To solve this problem, databases, such as DB2® for example, store a LOB in a specific LOB table space, and a LOB descriptor is stored in the database row. The LOB descriptor points to the storage position of the LOB in the LOB table space. In some instances, however, the size of a LOB may be small. The smaller sized LOB may be stored in a database table directly, which provides increased data access performance when accessing the LOB. This method of storing smaller LOBs is called the inline LOB technique.